Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly, idempotent, non-destructive and not-open-world, so the safety profile is covered. The description adds one useful behavioral fact, 'Costs no units,' which is not in the structured data. Beyond that it does not describe caching, latency, or scope limits, so it is adequate but not rich.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with the core claim ('Every key and range a shot document may use'), followed by an enumeration and two short supporting notes. It is dense but every sentence contributes; the enumeration is long but purposeful for a schema reference.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With an output schema present, the description need not explain return values, and for a zero-parameter reference tool it adequately summarizes the content's scope and the world-key cross-reference. It is complete enough to use, though it could name related schema tools more explicitly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool takes zero parameters, so the baseline is 4. The description correctly implies no input is required, and nothing about parameters is left ambiguous.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a concrete resource and scope: the set of keys and ranges a shot document may use, broken into camera, sun, air/fog, and subjects. This lets an agent recognize it as a schema/reference tool rather than an action tool. It does not explicitly contrast itself with sibling schema tools like video_schema or raster_check, so it falls short of full sibling differentiation.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no explicit when-to-use or when-not-to-use guidance. The mention that the same keys go in a video clip's extra and the pointer to raster_render are cross-references, not routing instructions. An agent must infer that this is the reference to consult before authoring a shot.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.